// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This provides a wrapper around system calls which may be interrupted by a
// signal and return EINTR. See man 7 signal.
// To prevent long-lasting loops (which would likely be a bug, such as a signal
// that should be masked) to go unnoticed, there is a limit after which the
// caller will nonetheless see an EINTR in Debug builds.
//
// Don't wrap close calls in HANDLE_EINTR. Use IGNORE_EINTR if the return
// value of close is significant. See http://crbug.com/269623.

// By: wlmwang
// Date: Jun 02 2019

#ifndef ANT_EINTR_WRAPPER_H_
#define ANT_EINTR_WRAPPER_H_

#include <errno.h>

#if defined(NDEBUG)
#define HANDLE_EINTR(x) ({ \
	decltype(x) eintr_wrapper_result; \
	do { \
		eintr_wrapper_result = (x); \
	} while (eintr_wrapper_result == -1 && errno == EINTR); \
	eintr_wrapper_result; \
})

#else
#define HANDLE_EINTR(x) ({ \
	int eintr_wrapper_counter = 0; \
	decltype(x) eintr_wrapper_result; \
	do { \
		eintr_wrapper_result = (x); \
	} while (eintr_wrapper_result == -1 && errno == EINTR && \
			 eintr_wrapper_counter++ < 100); \
	eintr_wrapper_result; \
})

#endif  // NDEBUG

#define IGNORE_EINTR(x) ({ \
	decltype(x) eintr_wrapper_result; \
	do { \
		eintr_wrapper_result = (x); \
		if (eintr_wrapper_result == -1 && errno == EINTR) { \
			eintr_wrapper_result = 0; \
		} \
	} while (0); \
	eintr_wrapper_result; \
})

#endif  // ANT_EINTR_WRAPPER_H_
